I have no heat for about 3-5 miles depending on outside temp until temp guage reaches normal?

2002 330 After seeing signs ofleaking coolant, the local BMW shop former dealer told me the water pump was leaking. They replaced the waterpump and thermostat. Now I have no heat for about 3-5 miles depending on outside temp until temp guage reaches normal, at which time the low coolant light comes on and the heat finally starts to work. Previously I had heat in about 1 mile. Did they screw something up? System pressure tests good 3 hr. Coolant level is good at filler cap.

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[Kerry at Pelican Parts]

Try opening the bleed screw while the car is warming up. You may have an air pocket. Also look at the flow in the coolant expansion tank.

- Kerry